MAINTAINERS: add Paul Fertser as a NC-SI reviewer

Paul has been providing very solid reviews for NC-SI changes
lately, so much so I started CCing him on all NC-SI patches.
Make the designation official.

Reviewed-by: Paul Fertser <fercerpav@gmail.com>
Link: https://patch.msgid.link/20250123155540.943243-1-kuba@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

MAINTAINERS

@@ -16189,6 +16189,7 @@ F:	drivers/scsi/sun3_scsi_vme.c
 
 NCSI LIBRARY
 M:	Samuel Mendoza-Jonas <sam@mendozajonas.com>
+R:	Paul Fertser <fercerpav@gmail.com>
 S:	Maintained
 F:	net/ncsi/